全文获取类型
收费全文 | 500篇 |
免费 | 12篇 |
国内免费 | 4篇 |
专业分类
化学 | 259篇 |
晶体学 | 4篇 |
力学 | 31篇 |
数学 | 106篇 |
物理学 | 116篇 |
出版年
2023年 | 10篇 |
2022年 | 16篇 |
2021年 | 11篇 |
2020年 | 13篇 |
2019年 | 22篇 |
2018年 | 11篇 |
2017年 | 10篇 |
2016年 | 25篇 |
2015年 | 16篇 |
2014年 | 23篇 |
2013年 | 34篇 |
2012年 | 25篇 |
2011年 | 38篇 |
2010年 | 23篇 |
2009年 | 18篇 |
2008年 | 32篇 |
2007年 | 32篇 |
2006年 | 25篇 |
2005年 | 25篇 |
2004年 | 22篇 |
2003年 | 15篇 |
2002年 | 13篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 5篇 |
1997年 | 7篇 |
1996年 | 4篇 |
1989年 | 2篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1982年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1957年 | 1篇 |
1938年 | 1篇 |
1937年 | 1篇 |
1911年 | 1篇 |
1910年 | 1篇 |
1907年 | 1篇 |
1906年 | 2篇 |
1905年 | 1篇 |
1903年 | 1篇 |
1877年 | 1篇 |
1868年 | 1篇 |
排序方式: 共有516条查询结果,搜索用时 31 毫秒
461.
Supramolecular microcontact printing and dip-pen nanolithography on molecular printboards 总被引:1,自引:0,他引:1
Bruinink CM Nijhuis CA Péter M Dordi B Crespo-Biel O Auletta T Mulder A Schönherr H Vancso GJ Huskens J Reinhoudt DN 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(13):3988-3996
The transfer of functional molecules onto self-assembled monolayers (SAMs) by means of soft and scanning-probe lithographic techniques-microcontact printing (muCP) and dip-pen nanolithography (DPN), respectively-and the stability of the molecular patterns during competitive rinsing conditions were examined. A series of guests with different valencies were transferred onto beta-cyclodextrin- (beta-CD-) terminated SAMs and onto reference hydroxy-terminated SAMs. Although physical contact was sufficient to generate patterns on both types of SAMs, only molecular patterns of multivalent guests transferred onto the beta-CD SAMs were stable under the rinsing conditions that caused the removal of the same guests from the reference SAMs. The formation of kinetically stable molecular patterns by supramolecular DPN with a lateral resolution of 60 nm exemplifies the use of beta-CD-terminated SAMs as molecular printboards for the selective immobilization of printboard-compatible guests on the nanometer scale through the use of specific, multivalent supramolecular interactions. Electroless deposition of copper on the printboard was shown to occur selectively on the areas patterned with dendrimer-stabilized gold nanoparticles. 相似文献
462.
463.
Simona Irrera Stefano Turchini Simone Sanna Paolo Moras Corrado Crotti Tommaso Prosperi 《Surface science》2007,601(13):2562-2565
Adsorption of d-alaninol on Cu(1 0 0) at room temperature has been investigated by photoelectron spectroscopy in the soft X-ray and VUV energy range and low energy electron diffraction (LEED). d-Alaninol was found by LEED to self-assemble at full coverage; core and valence photoemission spectra are presented at low and full coverage. Chemisorption occurs at room temperature. The bonding at low coverage takes place at the hydroxylic group; at full coverage there is evidence of bonding for both hydroxylic and amino groups. 相似文献
464.
465.
Motivic integration [M. Kontsevich, Motivic integration, Lecture at Orsay, 1995] and MacPherson's transformation [R. MacPherson, Chern classes for singular varieties, Ann. of Math. 100 (1974) 423-432] are combined in this paper to construct a theory of “stringy” Chern classes for singular varieties. These classes enjoy strong birational invariance properties, and their definition encodes data coming from resolution of singularities. The singularities allowed in the theory are those typical of the minimal model program; examples are given by quotients of manifolds by finite groups. For the latter an explicit formula is proven, assuming that the canonical line bundle of the manifold descends to the quotient. This gives an expression of the stringy Chern class of the quotient in terms of Chern-Schwartz-MacPherson classes of the fixed-point set data. 相似文献
466.
467.
In this paper, we give a more direct proof of the results by Clair and Mokhtari-Sharghi [B. Clair, S. Mokhtari-Sharghi, Zeta functions of discrete groups acting on trees, J. Algebra 237 (2001) 591-620] on the zeta functions of periodic graphs. In particular, using appropriate operator-algebraic techniques, we establish a determinant formula in this context and examine its consequences for the Ihara zeta function. Moreover, we answer in the affirmative one of the questions raised in [R.I. Grigorchuk, A. ?uk, The Ihara zeta function of infinite graphs, the KNS spectral measure and integrable maps, in: V.A. Kaimanovich, et al. (Eds.), Proc. Workshop, Random Walks and Geometry, Vienna, 2001, de Gruyter, Berlin, 2004, pp. 141-180] by Grigorchuk and ?uk. Accordingly, we show that the zeta function of a periodic graph with an amenable group action is the limit of the zeta functions of a suitable sequence of finite subgraphs. 相似文献
468.
We consider the system of moments associated with the relativistic Boltzmann-Chernikov equation. Using the particular symmetric
form obtained by the closure procedure of Extended Thermodynamics we deduce a lower bound for the maximum velocity of wave
propagation in terms of the number of moments for a non-degenerate gas. When the number of moments increases this velocity
tends to the speed of light. We also give the lower bound estimate in the limit cases of ultrarelativistic fluids and in the
non relativistic approximation.
Received September 28, 1998 相似文献
469.
V. V. Mikhailov O. Adriani G. A. Bazilevskaya G. C. Barbarino R. Bellotti E. A. Bogomolov M. Boezio V. Bonvicini M. Bongi S. Bottai A. Bruno A. Vacchi E. Vannuccini G. I. Vasilyev S. A. Voronov A. M. Galper C. De Santis V. Di Felice G. Zampa N. Zampa M. Casolino D. Campana A. V. Karelin P. Carlson G. Castellini F. Cafagna A. A. Kvashnin A. N. Kvashnin S. V. Koldashov S. A. Koldobskiy S. Y. Krutkov A. A. Leonov A. G. Mayorov V. V. Malakhov M. Martucci L. Marcelli W. Menn M. Merge E. Mocchiutti A. Monaco N. Mori R. Munini G. Osteria B. Panico P. Papini P. Picozza M. Pearce M. Ricci S. B. Ricciarini M. F. Runtso M. Simon R. Sparvoli P. Spillantini Y. I. Stozhkov Y. T. Yurkin 《Bulletin of the Russian Academy of Sciences: Physics》2017,81(2):154-156
The PAMELA magnetic spectrometer was launched aboard the Resurs DK-1 satellite into a nearpolar circumterrestrial orbit with an altitude of 350–600 km to study fluxes of the particles and antiparticles of cosmic rays in the wide energy range of ~80 MeV to several hundred gigaelectronvolts. The results from observations of temporal variations in electron and positron fluxes in 2006–2015 are presented. The ratio of electron and positron fluxes measured in this time interval reveals a dependence on the rigidity of particles, the solar activity, and the polarity of the solar magnetic field. 相似文献
470.
E. A. Bogomolov O. Adriani G. A. Bazilevskaya G. C. Barbarino R. Bellotti M. Boezio V. Bonvicini M. Bongi S. Bottai A. Bruno A. Vacchi E. Vannuccini G. I. Vasilyev S. A. Voronov A. M. Galper C. De Santis V. Di Felice G. Zampa N. Zampa M. Casolino D. Campana A. V. Karelin P. Carlson G. Castellini F. Cafagna A. A. Kvashnin A. N. Kvashnin S. V. Koldashov S. A. Koldobskiy S. Y. Krutkov A. A. Leonov A. G. Mayorov V. V. Malakhov M. Martucci L. Marcelli W. Menn M. Merge V. V. Mikhailov E. Mocchiutti A. Monaco N. Mori R. Munini G. Osteria B. Panico P. Papini P. Picozza M. Pearce M. Ricci S. B. Ricciarini M. F. Runtso M. Simon R. Sparvoli P. Spillantini Y. I. Stozhkov Y. T. Yurkin 《Bulletin of the Russian Academy of Sciences: Physics》2017,81(2):132-135
The first results from measuring the spectra of solar neutrons with energies of ~10–1000 MeV in the solar flares of 2006–2015 observed by the PAMELA international space experiment are presented. The PAMELA neutron detector with 3He counters and a moderator with an area of 0.18 m2 allows us to estimate the flux of solar neutrons during solar flares. Solar neutrons with energies of ~10–1000 MeV likely occurred in 21 out of the 24 analyzed flares of 2006–2015. 相似文献